Pressure regulator for a fuel supply unit

ABSTRACT

Disclosed is a pressure regulator for a fuel supply unit of a motor vehicle comprising a valve for joining a connection to an outlet above a designated pressure in the connection, a valve body and a valve seat, and a spring element for prestressing the valve body against the valve seat, characterized in that the valve body is designed as a sheet-metal part.

BACKGROUND OF THE INVENTION

The invention relates to a pressure regulator for a fuel supply unit ofa motor vehicle, with a valve for joining a connection to an outletabove a designated pressure in the connection, with a valve body and avalve seat, and with a spring element for prestressing the valve bodyagainst the valve seat.

Pressure regulators of this type are frequently used in motor vehiclesnowadays to regulate a pressure in a forward flow line leading to aninternal combustion engine, and are known from practice. The valve bodyis generally designed as a ball and provides a seal in relation to thevalve seat below a designated pressure. The outlet is arranged on thatside of the valve seat which lies opposite the connection. Above thedesignated pressure, the ball is raised from the valve seat by thepressure in the connection such that fuel can flow to the outlet. Forthe required tightness, the ball has to have particularly precisedimensions and a surface with as little surface roughness as possible.The ball is therefore generally polished or lapped.

A drawback of the known pressure regulator is that it requires a verycomplicated manufacturing process to produce the valve body.Furthermore, the valve body, which is designed as a ball, requirescomplicated guidance in the pressure regulator.

The invention is based on the problem of designing a pressure regulatorof the type mentioned at the beginning in such a manner that it isconstructed in a particularly simple manner structurally and iscost-effective to manufacture.

BRIEF DESCRIPTION OF THE INVENTION

This problem is solved according to the invention in that the valve bodyis designed as a sheet-metal part.

This design enables the valve body to be guided in a particularly simplemanner. Since the sheet-metal part can be manufactured to besubstantially lighter and flatter than the ball of the known pressureregulator, the pressure regulator according to the invention hasparticularly small dimensions. Furthermore, the valve body can bemanufactured particularly cost-effectively, for example by punching. Bythis means, the pressure regulator according to the invention isconstructed in a particularly simple manner structurally and can bemanufactured cost-effectively.

Tolerance compensation between the valve seat, which is arranged on abore, and the valve body can be produced in a simple manner, accordingto an advantageous development of the invention, if the valve body is inthe form of a spherical cap on its side facing the valve seat. A furthersubstantial advantage is that the spherical cap has a smaller axialextent than a ball, as a result of which the valve body according to theinvention can be designed to be particularly flat, and therefore thevalve body requires less constructional space in the axial extent. Inaddition, the spherical cap can be manufactured in a simple manner bydeformation of the sheet-metal part.

The installation of the valve body turns out to be particularly simple,according to another advantageous development of the invention, if thevalve body has latching hooks for securing on a support part.

The joining of the latching hooks to the support part is simplified ifthe support part has correspondingly designed receptacles for thelatching hooks.

According to another advantageous development of the invention, thevalve body does not require a complicated guide if the latching hookshave a designated play, in particular radial play, in relation to thesupport part. This has the advantage that, as a result of the play,radial tolerance compensation is made possible.

In addition to the radial tolerance compensation, tolerances in theaxial extent between the valve body and the valve seat can also becompensated for in a simple manner by, according to another advantageousdevelopment of the invention, the valve body having spring tonguessupported on the support part. Use is made here of the fact that thelatching hooks of the valve body have axial play in relation to thereceptacles on the support part. The valve body can thereby beprestressed axially in interaction with the striking of the latchinghooks against the support part and the spring tongues.

A further advantage of the spring tongues is that a particularly shallowcharacteristic curve of the pressure regulator can be achievedtherewith, since the spring tongues also raise the valve body when thepiston is moved upwards.

The valve body can be prestressed and/or guided in a tilt-free manner,according to another advantageous development of the invention, if ithas at least three spring tongues and/or at least three latching hooks.

According to another advantageous development of the invention, atorsion-resistant securing of the valve body can be produced withparticularly little structural outlay if the spring tongues and thelatching hooks are distributed in an alternating manner over thecircumference of the valve body.

In the case of the known pressure regulator, when the valve body, whichis designed as a ball, strikes against the valve seat, annoying noisesarise. Noises can be reliably avoided, according to another advantageousdevelopment of the invention, if that side of the valve body which facesthe valve seat has a coating. Furthermore, this ensures reliabletightness in the connection at low pressures.

The tightness of the valve body in relation to the valve seat is furtherincreased, according to another advantageous development of theinvention, if the coating is produced from an elastomer. In particular,acrylonitrile-butadiene-rubber (NBR) or fluorocaoutchouc, which is knownunder the trade name Viton, are suitable as a coating for a high degreeof tightness, low tendency of the valve body to stick on the valve seatand low noise emission.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention permits numerous embodiments. To further clarify its basicprinciple, one of these is illustrated in the drawing and is describedbelow. In the drawing

FIG. 1 shows a longitudinal section through a pressure regulatoraccording to the invention,

FIG. 2 shows a greatly enlarged, perspective illustration of a valvebody of the pressure regulator according to the invention from FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a pressure regulator, according to the invention anddesigned as a through flow valve, with a housing 1 and a piston 2arranged displaceably in the housing 1. The pressure regulator serves tolimit a maximum pressure in a forward flow line (not illustrated) of afuel tank of a motor vehicle. The housing 1 has two housing parts 4, 5kept at a distance by a support part 3. The pressure regulator has aconnection 6 for a pressure line, and an outlet 7. The piston 2 isprestressed with a valve seat 9 against a valve body 10 by means of aspring 8 designed as a helical spring.

A membrane 11, which is connected to the support part 3 and the piston2, seals off the region below the piston 2 from the region above thepiston 2. This ensures that, when there is a pressure in the connection6, the piston 2 is loaded counter to the force of the spring 8 and,above a designated pressure, the piston 2 is moved such that the valveseat 9 lifts off from the valve body 10. Therefore, above the designatedpressure, fuel can escape from the connection 6 through the outlet 7.The housing parts 4, 5 are manufactured from steel sheet and are joinedto each other by a flanging 12. By means of the flanging 12, a sealingring 13 is prestressed against the support part 3 and the lower housingpart 5. An edge 14 of the upper housing part 4, which edge holds thespring 8, is designed such that it is plastically deformable and servesto calibrate the pressure regulator and therefore to set the designatedpressure at which the join between the connection 6 and the outlet 7 isproduced.

The valve body 10 is designed as a sheet-metal part and has springtongues 15 and latching hooks 16. The valve body 10 is joined to thesupport part 3 by the latching hooks 16, with the latching hooks 16being in engagement with receptacles 18 of the support part 3. Thelatching hooks 16 are designed with radial and axial play with respectto the receptacles 18. The valve body 10 is prestressed in the axialdirection via the spring tongues 15 and the latching hooks 16, whichbear against the receptacles 18, with the spring tongues 15 permitting aslight movement of the valve body 10 in the axial direction. The freeend of the spring tongues 15 is arranged in a radially displaceablemanner thereto on the support part 3. As a result of the radial play ofthe latching hooks 16 in relation to the receptacles 18 on the supportpart 3, the valve body 10 is also arranged movably in the radialdirection, and therefore the radial tolerance compensation is possibleas a result. Furthermore, FIG. 1 shows that that region of the valvebody 10 which is opposite the valve seat 9 is designed as a sphericalcap.

FIG. 2 shows a greatly enlarged perspective illustration of the valvebody 10, which is designed as a sheet-metal part, from FIG. 1. Toclarify the shape of the valve body 10, a section is shown in theillustration. It can be seen here that the valve body 10 has threelatching hooks 16 and spring tongues 15 in each case. The latching hooks16 and the spring tongues 15 are each distributed at distances of 120°over the circumference of the valve body 10 and are arranged in analternating manner to one another. Furthermore, FIG. 2 shows that thevalve body 10 has a coating 17 of an elastomer on its side facing thevalve seat 9 illustrated in FIG. 1.

1. A pressure regulator for a fuel supply unit of a motor vehicle,comprising: a valve for joining a connection to an outlet above adesignated pressure in the connection; a valve body; a moveable valveseat; a spring element for prestressing the valve seat against the valvebody; and a support part joined to the valve body and arranged withinthe pressure regulator to maintain two opposing housing parts of thepressure regulator at a spaced apart distance from each other; whereinthe valve body is a sheet-metal part.
 2. The pressure regulator asclaimed in claim 1, wherein the valve body comprises a spherical cap ona side of the valve body facing the valve seat.
 3. The pressureregulator as claimed in claim 1, wherein that side of the valve bodywhich faces the valve seat is provided with a coating.
 4. The pressureregulator as claimed in claim 3, wherein the coating is produced from anelastomer.
 5. The pressure regulator as claimed in claim 1, wherein thevalve body includes latching hooks for securing the valve body on thesupport part within the pressure regulator.
 6. The pressure regulator asclaimed in claim 5, wherein the support part includes receptacles forreceiving the latching hooks of the valve body.
 7. The pressureregulator as claimed in claim 5, wherein the latching hooks are providedwith at least one of radial and axial play in relation to the supportpart within the pressure regulator.
 8. The pressure regulator as claimedin claim 5, wherein the valve body includes spring tongues which aresupported on the support part within the pressure regulator.
 9. Thepressure regulator as claimed in claim 8, wherein ends of the springtongues are arranged in at least one of a radially and axiallydisplaceable manner in the support part within the pressure regulator.10. The pressure regulator as claimed in claim 8, wherein the valve bodyincludes one of at least three spring tongues and at least threelatching hooks.
 11. The pressure regulator as claimed in claim 8,wherein the spring tongues and the latching hooks are distributed in analternating manner over a circumference of the valve body.
 12. Apressure regulator for a fuel supply unit of a motor vehicle,comprising: a valve for joining a connection to an outlet above adesignated pressure in the connection; a valve body having latchinghooks for securing the valve body on a support part of the pressureregulator; a moveable valve seat; and a spring element for prestressingthe valve seat against the valve body; wherein the valve body is asheet-metal part including spring tongues which are supported on thesupport part within the pressure regulator.
 13. The pressure regulatoras claimed in claim 12, wherein the support part includes receptaclesfor receiving the latching hooks of the valve body.
 14. The pressureregulator as claimed in claim 12, wherein the latching hooks areprovided with at least one of radial and axial play in relation to thesupport part within the pressure regulator.
 15. The pressure regulatoras claimed in claim 12, wherein ends of the spring tongues are arrangedin at least one of a radially and axially displaceable manner in thesupport part within the pressure regulator.
 16. The pressure regulatoras claimed in claim 12, wherein the valve body includes one of at leastthree spring tongues and at least three latching hooks.
 17. The pressureregulator as claimed in claim 12, wherein the spring tongues and thelatching hooks are distributed in an alternating manner over acircumference of the valve body.